Polishing is used widely within the microelectronics industry. Smaller feature sizes are requiring workpieces to be planarized to allow lithographic operations to be performed properly. In another application, some metals, such as copper, are not readily removed by dry etching techniques. An inlaid process sequence can be performed wherein a metal layer is deposited over a patterned insulating layer and within openings of the patterned insulating layer. Polishing can be used to remove the metal lying outside openings of the patterned layer, leaving an inlaid metal pattern corresponding to contacts, vias, or interconnects.
Within the microelectronics industry, polishing is performed as chemical-mechanical polishing, also known as chemical-chemical mechanical planarization, which involves a chemical reacting or interaction between an exposed surface of the workpiece and a component of a polishing slurry to form a polishing product. Abrasive particles within the polishing slurry remove the polishing product to expose an underlying portion of workpiece. The polishing continues until a substantially planar surface is achieved, a sufficient amount of a layer is removed, another criterion is met, or any combination thereof. The development of chemical-mechanical polishing slurries can be challenging because of potential adverse interactions between the components within the slurry, the layer being polished during polishing, a different layer that may become exposed during polishing, or any combination thereof.
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